Electrical socket



Aug. 13, 1940.. c KNUTSQN 2,211,726

ELECTRICAL SOCKET Filed March 5, 1938 Invenior: Ca 2 3 L. Knaiflion.

Patented Aug. 13, 1940 UNITED STATES ELECTRICAL SOCKET Carl L. Knutson, Elmhurst, 111., assignor to Cinch Manufacturing Corporation, Chicago, 111., a

corporation of Illinois Application March 5,

3 Glaims.

This invention relates to sockets such as are used in radio apparatus for holding electron tubes having rod-like terminals for electrodes. The-invention relates also to improved contact 5 springs for a socket member and to an installation'including a socket member having my improved contact springs and a tube member having rod-like electrodes of specific construction received by the contact springs of the socket member.

Heretoiore it has been common practice to secure contact springs to a socket base through means of ears extending laterally from one end of the contact spring and disposed between superposed insulating plates of the base. However, it has been found that with theknown constructions the ears of adjacent springs are so closely disposed that there is a tendency for leakage between them.

An object of my invention is the provision of a plug and socket installationwherein portions of adjacent rod-like terminals of the plug member are closer together than portions of respective contact springs of the socket member in engagement with the rod-like terminals wherein any leakage at radio frequencies must take place through the rod-like terminals, and not through the contact springs.

A further object of my invention is to provide springs wherein the contact springs are formed to grip resiliently and efficiently a cooperating rod-like terminal of a tube member.

Another object is the provision of an improved contact spring adapted for rapid production in large quantities.

Further objects of my invention will be apparent from inspection of the drawing and specification herein set forth.

Referring to the drawing, in which I have illustrated a preferred embodiment of my invention:

Figure 1 is a plan view of a socket member embodying the present invention;

Fig. 2 is a bottom view of the socket member shown in Fig. 1;

Fig, 3 is a section taken along the line 3-4 of Fig. 1 and showing a portion of a radio tube in spaced relation therewith;

Fig. 4 is a view similar to Fig. l, but with an insulating plate removed showing the contact springs;

Fig. 5 is a section taken along the line 3-3 of Fig. 1;

a socket member having my improved contact' 1938, Serial No. 194,129

Fig. 6 is an enlarged bottom view of one of my improved contact springs per se Fig. 7 is an enlarged top view of the contact spring shown in Fig. 6; and

Fig. 8 is an enlarged section taken along the line 8-8 of Fig. 5.

Referring to the drawing, my preferred form of socket member includes a base member i comprising an upper plate 2 and a lower plate 3 formed of suitable insulating material. Contact springs 4 are carried. by the base i, and the plates 2 and 3, together with the contact springs, are held together in the assembled socket member by a sheet metal supporting member 5. The supporting member 5 has a dished ring por- 16 tion 6 having flanges ll at opposed ends which are aperture to receive suitable attaching means for securing the socket member to the under side of a supporting panel (not shown). The ring portion 6 has lug portions 8 in clamped engagement with the top surface of the insulating plate 2 for holding the parts of the socket member in assembly (Fig. 1). In my preferred form the ring member 6 has projections-9 engaging with cooperating notches Iii in the insulating plates 2 and 3 for preventing relative rotation of the parts. The lower insulating plate 3 has apertures ll therein arranged in substantially circular relation about the center and adapted to receive the contact springs 4, which have supporting ears disposed between the plates 2 and 3. The upper plate 2 has apertures l2 whereby rod-like terminals I3, projecting beyond one end of a tube base it, pass through the apertures l2 into engagement with the contact springs 4 (Fig. 5). The plates 2 and 3 preferably have aligned central apertures II and I2 of non-circular shape for receiving a correspondingly shaped guide pin M of the tube member, but this feature formsno part of my present invention as it is well known in the art. The rod-like contacts l3, which I have chosen for the purpose of illustrating my invention, are preferably of the tube type now widely u'sed commercially and have a bead 15 adjacent the tube base I4 for aiding to secure the rod-like contacts to the tube base, as will be understood by those skilled in the art.

Referring in detail to my improved spring contact members 4, I have shown contacts having a back portion l6 which is preferably straight and a wire-receiving portion H at one end which may be bent into any suitable form, such, for example, as illustrated in Figs. 5 and 6. A short Side portion It! and a long side portion l9 extend from opposed edges of the back portion l6 and are bent u to form an enclosed region for receiving a co= operatin rod-like terminal of a tube member and resiliently engaging the same. The long side portion I9 has a portion 19' extending away from the base portion l6 and forming an acute angle therewith. The long side has a free end portion 20 extending substantially toward the back portion and a portion 2| between the portions 19' and 20 in direct opposite relation to the back portion l6, as most clearly shown in Fig. 8. The short arm 18 extends toward the free end portion 20 of the arm l9 and the arms I8 and [9 have separated free edges 22 and 23 respectively intermediate that edge of the back portion Hi from which the arm 19 extends and the free end portion 20 of the long arm l9 (Figs. 6, '7 and 8). As a result of the particular construction of the rodreceiving portion of the contact spring, wherein one arm is formed to have a substantially greater length than the other arm, greater spring action is provided by the longer arm efiecting a good resilient engagement of the arm with a rod-like terminal. Furthermore, the rod-like terminal is engaged by four portions of the contact spring; namely, the back portion 56, the free edges 22 and 23 of the arms l8 and i9 respectively, and the outwardly-extending portion it of the long arm, as most clearly shown in Fig. 8, so as to insure an excellent electrical contact between the parts. As a means for assembling the contact spring with the base I I have provided a supporting ear 24 extending laterally from the back portion 16 and a supporting ear 25 extending laterally from the portion 2! in direct opposite relation to the ear 24. The ears 24 and 25 are adapted for supporting engagement with the upper surface of the insulating plate 3, as most clearly shown in Figs. 4 and 5, for limiting movement of the spring contacts through the apertures H. It will be noticed that the particular construction of the contact spring, wherein the slot between the edges 22 and 23 is positioned at one side of the contact spring, enables the ears 2d and 25 to be disposed at opposite ends of the contact spring with the result that respective ears 2% and 25 of adjacent contact springs are disposed no nearer each other than the respective side portions l8 and IQ of the adjacent contact springs. Furthermore, it will be seen from inspection of Fig. 8 that when the rod-like terminals l3 are engaged with the contact springs 4, the beads I 5 of adjacent rod-like terminals extend laterally beyond the side portions l8 and I 9 with the result that the beads of adjacent rod-like terminals are closer together than portions of adjacent contact springs. As a result oi this construction, any leakage at radio frequencies must take place between the rod-like terminals and not between the contact springs.

Assembly of the parts oi? my socket member is easily carried out through first inserting the contact springs through the apertures H of the insulating plate 3 with the wire-receiving portions ll being first entered through the apertures so that the supporting ears 2 2 and 25 engage the upper surface of the plate 3. Next, the insulating 2,21 was plate 2 is superposed above the plate 3 with the apertures I2 of the plate 2 in substantial alignment with the terminal-receiving regions of the contact springs 4. Finally, the parts are assembled with the metal holder 5 by the means hereinabove described. In the preferred form of my invention the contact springs 4 are fitted so close- 1y within respective apertures l I of the insulating plate 3 that there is no chance for portions of adpacent contact springs to move into closer relation to one another than the beads l 5 of adjacent rod-like terminals l3 when the terminals are in engagement with the contact springs 4 whereby no leakage can take place between the contact springs for the reasons hereinabove set forth.

Although I have illustrated and described a preferred embodiment of my invention, I do not wish to be limited thereby because the scope of my invention is best defined by the following claims.

I claim:

A contact spring having a non-circular contact pin-receiving portion provided with a back portion and a pair of side portions extending from opposed edges of said back portion, one of said side portions being longer circumferentially of the pin-receiving portion than the other, said longer side portion having a portion extending outwardly away from said back portion, a free end portion extending inwardly toward said back portion, said side portions having separated free edges, a portion of said longer side portion between said outwardly-extending portion and said free end portion being positioned in opposite relation to said back portion, and a supporting ear extending from said back portion and a supporting ear extending from the oppositely-spaced portion of said longer side at one end of the pin-receiving portion substantially as described.

2. A contact spring having an elongated prongreceiving tubular portion of substantially triangular cross-sectional shape, one of the sides of said tubular portion having free edges at opposed longitudinal ends thereof disposed in the normal plane of said side, said side having a slit extending entirely through the length thereof so that the edges of the tubular portion adjacent the slit make line contacts with a contact prong of circular cross-section and a support-engaging portion at one end of said tubular portion extending substantially transversely to the axis of said tubular portion.

3. A contact spring having an elongated tubular portion of substantially triangular cross-sectional shape, one of the sides of said tubular portion having a slit extending the length thereof so that the edges of the tubular portion adjacent the slit make line contacts with a contact prong of circular cross-section, a soldering lug integral with and forming a continuation of the end of another of said sides and a support-engaging portion at the end of said tubular portion opposite from said soldering lug extending substantially transversely to the axis of said tubular portion.

CARL L. KNUTSON. 

